Keep in mind that this is a kid's (or at least family) game. Levels can't be very long, they would get bored quick. I personally like the smaller levels because it means that if I only have 30 minutes to play, I can still sit through a level to kill time. Much like Mario Bros and the likes.

I agree that if they are very short, there should be a lot of them though. 8 short levels would not be a very good experience.

Yes but this level was not even half as long as those of the original toybox... But maybe it was just the introduction to the toybox games. As there was no menu/startscreen there's no way to tell how far into the game that was.